Patent GB-299774-A (GB)
Title: Improvements in machines for assembling screw-threaded tyre valve components
IPC: B23P19/06
Filed: 1928-10-19
Abstract: 299,774. Schrader's Son, Inc., A., (Assignees of Spill, C. J.). Oct. 31, 1927, [Convention date]. Bolts, nuts and screws, assembling.-A machine for assembling screwed components is described with particular reference to assembling parts of tyre valves, and comprises means for supplying blanks from two distinct hoppers to separate work turrets, which at one station align the two parts axially with one another and with a frictionally-driven screwdriver which effects the assembly, the assembled unit being discharged to a shoot at a further turret station. Blanks, transferring.-The valve exteriors or internally-threaded members are dumped into a hopper 103, Fig. 1, provided with a vertically oscillating blade driven by means not shown from a chain 287, Fig. 3, through a clutch 285 from the main shaft 51, under hand control by a yoke linked to a rock shaft 284 fitted with a lever 283, Fig. 2. The blanks are delivered to a shoot 102, and are fed to the shoot by an agitator 288 belt-driven at 291, Fig. 1, from one of the shafts for oscillating the hopper blade. Delivery of the blanks from the shoot is controlled by an escapement device consisting of levers 100, 101, Fig. 10, rocked by rods 128, 112 pivoted to levers 130, Fig. 14, operated by cams on the shaft 58 under the control of springs 133 and limiting stops 130'. The lever 100 carries inclined spring-controlled fingers pivoted to pass freely over the blanks when the lever moves towards the hopper but to grip them on the reverse movement. The lever 101 is linked to a bevel-ended latch that snaps past the end blank, whilst the remainder are temporarily held by the spring-controlled fingers, and then feeds it into a pair of recesses 104, 105, Fig. 4, in a turret 35. the valve interiors or internally threaded parts are dumped into a hopper 227, Fig. 1, pivoted at 176 and oscillated by a rod 295 connected to a bell crank actuated by a cam having a corrugated or wavy surface and driven by gears from the secondary cam shaft 83, Fig. 26, driven by bevel gearing from the main shaft 58, Fig. 14, driven by a worm 52, Fig. 3, on a shaft 294 driven through a clutch 57 and bevel gearing 54 on the main shaft 51 from a motor 50. To prevent this motor from being stalled in the event of obstruction to the working of the machine, the bevel gearing 54 is driven through an adjustable plate friction clutch 61. The clutch 57 is controlled by a hand lever 70 and spring 74, Fig. 2, and is held in engagement by a latch. The lever is linked at 304 to the controller 305 for the separate motor that drives the screw-driver spindle. The hopper 227 contains a slideway 228, Fig. 18, on to which the blanks are shaken, and in the case of valve interiors hang by their threaded ends 226<1> which have the largest diameter of the various members forming this component. This slideway leads over a narrower way 229 that engages the actual valve stem, the minimum diameter part. The parts pass in this condition to the continuation way 230, all with their screwed ends uppermost. At the lower end of the way an escapement device is fitted consisting of a transversely reciprocating member carrying bevelled fingers 232, 232<1>. The member is reciprocated by a lever 244, Figs. 1 and 21, from a rock shaft 243 operated through linkage from a cam on the shaft 83, the cam being in the form of a lug which gives the member a complete back and forward movement once during each revolution to release a blank when an aperture 220, Fig. 1, in the turret 41 is stationary in position to receive it. The parts enter the turret with the large (screwed) end downwards, and the inversion is effected by a lug 246, Fig. 21, at the bottom of the way 230 in connection with a curved surface 267. To facilitate proper entry of the part into the bushing 203, Fig. in the turret the following mounting and parts are provided. The bushings are mounted in sockets on the turret so as to be axially movable, being normally held by springs 222, Fig. 5, against limiting screws 223. A shoulder 221 engages and locates the part by means of its threaded end. When a part is to be received the bushing is raised against the de:- livery bush 205, Fig. 26, by a rod 202 lifted by a lever 206, Fig. 14, linked to a rod 164 operated by a cam lever 162. Stop devices.-To make sure that the part has fully entered the bushing 203 a test rod 250, Fig. 26, connected to a bell crank 253 is permitted to pass down through the bush 205 by a cam 256 under spring control 257. Shoufd the part have refused to enter the turret the rod is arrested and the roller 255 then fails to rock the bell crank 260 and remove the finger 262 from the path of a finger 258<1> on the cam shaft 83. In the result the bell crank 261 is rocked depressing the rod 264 and removing a latch 267 from a dog on the rod 72 allowing the spring 74, above described, to throw out the clutch 57 and stop the machine. Hand driving-device.-To enable the machine to be operated by hand, as when setting-up, the shaft 294, Fig 2 is provided with a hand wheel 293. Turrets.-The turret 35, Fig. 4, is mounted on a shaft 33 carrying gears 36, 37, and 34, of which the gear 34 is geared to a geneva wheel 95. Fig. 8, operated by u pin on an arm 93 bevel geared to the shaft 58. The gear 36 transmits this indexing movement through gears 97, 98 to a gear 42 fast on the turret 41. The gear 37 and a corresponding gear 43 serve to lock the turret by co-operation with plungers 270, 271 controlled by the secondary cam shaft 83. To change the set up to deel with valve exteriors of a different length, washers 39 are changed to vary the space between the two turrets, a corresponding change being made in washers 303 to effect a corresponding change in the position of the cover plate 107. Work-holders .-To hold the valve exterior in position during the screwing-in of the interior a spring plunger 179, Fig. 4, with a centre to engage the bore of the valve casing is depressed by a lever 173 mounted on a rock shaft 172 operated by an arm 171, Fig. 1. connected by a rod 166, Fig. 14, and an aldjustahe bar 169 to the rod 164 described above. Cuttings, removing-Other arms on the rock shaft 172 control valves to blow air through the valve exterior one before the screwing in station, and the other at a station subsequent thereto. At the latter station the blow-valve has means for depressing the stem of the interior valve member that has now been screwed in the casing in order to afford passage for the air. Yielding drive attachments.-The screwdriver 151 Fig. 5, is carried by a chuck 135 driven by a head 150 through a piston ring 154 controlled by springs 155 and screws 156. Concentric mounting is secured by a ball bearing 157. Spindles; screwing-up spindle feeds.-The chuck shank 149, Fig. 4, is mounted in a shouldered sleeve 159, a head on the shank being yieldingly pressed against the shoulder by a spring 160 confined bv a plug 158. The sleeve 159 is splined in a, sleeve 145 driven through worm gearing from the motor 136, and is fed by a lever 141 and cam on the shaft 58. The screw driver passes up through the bushing 203, which is raised at this station by a. block 210, Fig. 5,. with limiting flanges 211, 212 that control the movement of the bushing by the rounded end of a lever 215, Fig. 15 actuated by the rod 164 through the linkage shown. Blanks, ejecting.-After passing the second blowing-station the assembled valve is removed from the turret 35 by contact with a fixed incline and passes through a slot in the flange of the cover plate to a shoot, 282, Fig. 1, which dediversto a receptacle.